/**
 * Zero-dependency JSON diff.
 * Produces a flat list of changes between two plain objects.
 */
export type ChangeType = 'added' | 'removed' | 'changed';
export interface DiffEntry {
    /** Dot-separated path to the changed field (e.g. "address.city"). */
    readonly path: string;
    /** Type of change. */
    readonly type: ChangeType;
    /** Previous value (undefined for 'added'). */
    readonly from?: unknown;
    /** New value (undefined for 'removed'). */
    readonly to?: unknown;
}
/**
 * Compute differences between two objects.
 * Returns an array of DiffEntry describing each changed field.
 * Returns empty array if objects are identical.
 */
export declare function diff(oldObj: unknown, newObj: unknown, basePath?: string): DiffEntry[];
/** Format a diff as a human-readable string. */
export declare function formatDiff(changes: DiffEntry[]): string;